DNP3 event handling

[emgre]

Closes #50.

• The integrity-poll-ms was removed.
• There's a new section named polls where each poll is specified. There are two types of polls:
  • integrity sends a Class 1230
  • event, sends events classes scan according to the class1, class2 and class3 config values.
• Each profile has an associated poll to it. Therefore, for event profiles, it is possible to have an event poll and associate to it. An OpenFMB message will be generated when DNP3 events are received.
• It is possible to associate a profile with the special unsolicited poll, for generating messages on unsolicited responses.

name: device1  # This name is pre-pended to each log message
channel:
  adapter: 0.0.0.0  # Override to use a specific adapter
  outstation-ip: 127.0.0.1
  port: 20000
protocol:
  master-address: 1
  outstation-address: 10
  unsol-class-1: false
  unsol-class-2: false
  unsol-class-3: false
polls:
  - name: integrity_poll
    type: integrity
    interval-ms: 5000
  - name: event_poll
    type: event
    interval-ms: 2000
    class1: true
    class2: true
    class3: true
profiles:
  - name: BreakerEventProfile
    poll-name: event_poll
    mapping:  # profile model starts here
      [...]